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1 <br />1 <br />' 4. According to Colowyo personnel, no seepage problems <br />ixave been observed. lluring oux• site visit, the fill <br />appeared dry with no evidence of water or seepage <br />within the fill or along the face of tt~e lifts. <br />1 <br />5. Along several dozer cuts in Lift 1, we were able to <br />' examine about a 12-foot-thick section of the fill. The <br />fill appeared relatively homogenous in composition and <br />density and showed no evidence of nesting of boulders. <br />' Stability Analysis <br />We performed a stability analysis of both the current and <br />' final dump configuration, using MSLOPE, which is a stability <br />program developed by GAI. The program utilizes Bislxop's <br />' simplified method of analysis, which assumes a circular failure <br />surface. Given tt~e.slope geometry, soil properties, and water <br />' conditions, ttxe program will determine tlxe minimum factor of <br />safety and define the theoretical failure surface. The pore <br />' Pressure conditions are represented in the program by the factor <br />Ru which is defined on Figure 3. Given a 3:1 slope, an Ru value <br />of 0.46 represents a totally saturated slope with the phreatic <br />' surface coincident with the surface of the slope. An Ru of zero <br />represents a dry slope. <br />' In order to evaluate the strength of the spoil, we assumed <br />' that Lift 1, whicix is 200 feet }xigh with a slope angle of 38°, <br />has a Factor of Safety of 1.0. We further made the assumption <br />' that tt~e slope is dry and the fill has a unit weight of 125 psf. <br />Based on these assumptions, the following sets of strength <br />parameters are consistent with a Factor of Safety of 1.0: <br />1 <br />Case I Q = 38° (angle of friction) <br />c = 0 (colxesion) <br />5 <br />' Golder Associates <br />